Asset tracking systems are used to track the locations of assets in a facility. These systems may be used as part of a process control system or as part of a security system allowing the systems to identify when assets enter predefined areas or when assets are moved to or from their designated locations.
Asset tracking systems may be implemented using an asset tag attached or fixed to an asset. The asset tag periodically sends signals or “beacons” that are received by any number of readers at fixed locations throughout the facility. The readers use the signals to measure the distance between the asset tag and the readers. The readers then send the measurements to a central location, for example, by way of a mesh network. A system at the central location then uses the measurements from the readers to calculate the location of the asset.
Although such asset tracking systems are useful in keeping track of assets, they suffer from a lack of scalability and are prone to flooding as the number of asset tags increase. Accordingly, the capacity of the system (measured in terms of the number of tags that can be tracked/second) may be lower than desired for many applications. Although the beaconing rate of the asset tag could always be reduced in order to accommodate a higher number of tags, reducing the beaconing rate results in an increased lag time in providing a reliable location estimate because the most current information is not available should an asset start moving.